It is well-known that Leigh Mercer published his immortal "A man, a plan, a canal – Panama!" in the November 13 1948 issue of Notes & Queries. But was his the first discovery? I feel it unlikely that this palindrome remained undiscovered until such a relatively late date. My feeling is based on the following considerations:

The name PANAMA has been in the public consciousness since at least 1850, when a land crossing of the isthmus was one of the major routes to the California gold fields. De Lesseps' canal-building attempt in the 1880s, Panama's independence in 1903, and the subsequent U.S. construction of the Panama Canal were among the various events which made Panama a familiar name to any literate person in the Western world.

The period from 1860 to 1915 witnessed a flowering of public interest in various forms of wordplay and letterplay, including palindromes.

Words such as PANAMA which alternate vowels and consonants are particularly attractive to palindromists on account of the ease with which they may be palindromized. Words with many As in them are highly valued, since As can serve as indefinite articles in reverse.

Although it is regarded by many as a brilliant achievement, the fact is that the Panama palindrome virtually writes itself. Reverse PANAMA and you get A MAN, A P—. What's next? If you're like most word players, you're sensitized to rhymes, and so the natural thing to look for is a word which starts with P and rhymes with MAN. There are two common words, PAN and PLAN, and you will probably try both. When you have written down the PLAN version, you will note —NAL PANAMA runs in the other direction. What likely words end in —NAL? Of course, PANAMA immediately suggests CANAL. You write that down, and now you have A MAN, A PLAN, A C— on one side of your palindrome and —CANAL PANAMA on the other. Your palindrome is complete. Despite its serendipitous excellence, it is not a product of genius. Rather, it is mainly the result of the initial decision to try to palindromize PANAMA, after which the complete palindrome almost inevitably follows from the making of one or two easy and obvious decisions.

These are the reasons why I find it hard to believe that it could have taken almost one hundred years for the Panama palindrome to be noticed for the first time. I suspect that at least one previous incarnation of this palindrome lies forgotten in the mouldering pages of some turn-of-the-century journal or newspaper.